/*
 *  NIST SP800-38D compliant GCM implementation
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 *
 *  This file is provided under the Apache License 2.0, or the
 *  GNU General Public License v2.0 or later.
 *
 *  **********
 *  Apache License 2.0:
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  **********
 *
 *  **********
 *  GNU General Public License v2.0 or later:
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  **********
 */

/*
 * http://csrc.nist.gov/publications/nistpubs/800-38D/SP-800-38D.pdf
 *
 * See also:
 * [MGV] http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/gcm/gcm-revised-spec.pdf
 *
 * We use the algorithm described as Shoup's method with 4-bit tables in
 * [MGV] 4.1, pp. 12-13, to enhance speed without using too much memory.
 */

#if !defined(MBEDTLS_CONFIG_FILE)
#include "nettls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#if defined(MBEDTLS_GCM_C)

#include "nettls/gcm.h"
#include "nettls/platform_util.h"

#include <string.h>

#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
#include "nettls/aes.h"
#include "nettls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#include <stdio.h>
#define mbedtls_printf printf
#endif /* MBEDTLS_PLATFORM_C */
#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */

#if !defined(MBEDTLS_GCM_ALT)

/* Parameter validation macros */
#define GCM_VALIDATE_RET(cond) MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_GCM_BAD_INPUT)
#define GCM_VALIDATE(cond)     MBEDTLS_INTERNAL_VALIDATE(cond)

/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n, b, i) \
    { \
        (n) = ((uint32_t)(b)[(i)] << 24) | ((uint32_t)(b)[(i) + 1] << 16) | ((uint32_t)(b)[(i) + 2] << 8) | ((uint32_t)(b)[(i) + 3]); \
    }
#endif

#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n, b, i) \
    { \
        (b)[(i)] = (unsigned char)((n) >> 24); \
        (b)[(i) + 1] = (unsigned char)((n) >> 16); \
        (b)[(i) + 2] = (unsigned char)((n) >> 8); \
        (b)[(i) + 3] = (unsigned char)((n)); \
    }
#endif

/*
 * Initialize a context
 */
void mbedtls_gcm_init(mbedtls_gcm_context* ctx)
{
    GCM_VALIDATE(ctx != NULL);
    memset(ctx, 0, sizeof(mbedtls_gcm_context));
}

/*
 * Precompute small multiples of H, that is set
 *      HH[i] || HL[i] = H times i,
 * where i is seen as a field element as in [MGV], ie high-order bits
 * correspond to low powers of P. The result is stored in the same way, that
 * is the high-order bit of HH corresponds to P^0 and the low-order bit of HL
 * corresponds to P^127.
 */
static int gcm_gen_table(mbedtls_gcm_context* ctx)
{
    int ret, i, j;
    uint64_t hi, lo;
    uint64_t vl, vh;
    unsigned char h[16];
    size_t olen = 0;

    memset(h, 0, 16);
    if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, h, 16, h, &olen)) != 0)
        return (ret);

    /* pack h as two 64-bits ints, big-endian */
    GET_UINT32_BE(hi, h, 0);
    GET_UINT32_BE(lo, h, 4);
    vh = (uint64_t)hi << 32 | lo;

    GET_UINT32_BE(hi, h, 8);
    GET_UINT32_BE(lo, h, 12);
    vl = (uint64_t)hi << 32 | lo;

    /* 8 = 1000 corresponds to 1 in GF(2^128) */
    ctx->HL[8] = vl;
    ctx->HH[8] = vh;

    /* 0 corresponds to 0 in GF(2^128) */
    ctx->HH[0] = 0;
    ctx->HL[0] = 0;

    for (i = 4; i > 0; i >>= 1) {
        uint32_t T = (vl & 1) * 0xe1000000U;
        vl = (vh << 63) | (vl >> 1);
        vh = (vh >> 1) ^ ((uint64_t)T << 32);

        ctx->HL[i] = vl;
        ctx->HH[i] = vh;
    }

    for (i = 2; i <= 8; i *= 2) {
        uint64_t *HiL = ctx->HL + i, *HiH = ctx->HH + i;
        vh = *HiH;
        vl = *HiL;
        for (j = 1; j < i; j++) {
            HiH[j] = vh ^ ctx->HH[j];
            HiL[j] = vl ^ ctx->HL[j];
        }
    }

    return (0);
}

int mbedtls_gcm_setkey(mbedtls_gcm_context* ctx, mbedtls_cipher_id_t cipher, const unsigned char* key, unsigned int keybits)
{
    int ret;
    const mbedtls_cipher_info_t* cipher_info;

    GCM_VALIDATE_RET(ctx != NULL);
    GCM_VALIDATE_RET(key != NULL);
    GCM_VALIDATE_RET(keybits == 128 || keybits == 192 || keybits == 256);

    cipher_info = mbedtls_cipher_info_from_values(cipher, keybits, MBEDTLS_MODE_ECB);
    if (cipher_info == NULL)
        return (MBEDTLS_ERR_GCM_BAD_INPUT);

    if (cipher_info->block_size != 16)
        return (MBEDTLS_ERR_GCM_BAD_INPUT);

    mbedtls_cipher_free(&ctx->cipher_ctx);

    if ((ret = mbedtls_cipher_setup(&ctx->cipher_ctx, cipher_info)) != 0)
        return (ret);

    if ((ret = mbedtls_cipher_setkey(&ctx->cipher_ctx, key, keybits, MBEDTLS_ENCRYPT)) != 0) {
        return (ret);
    }

    if ((ret = gcm_gen_table(ctx)) != 0)
        return (ret);

    return (0);
}

/*
 * Shoup's method for multiplication use this table with
 *      last4[x] = x times P^128
 * where x and last4[x] are seen as elements of GF(2^128) as in [MGV]
 */
static const uint64_t last4[16] = {0x0000, 0x1c20, 0x3840, 0x2460, 0x7080, 0x6ca0, 0x48c0, 0x54e0,
                                   0xe100, 0xfd20, 0xd940, 0xc560, 0x9180, 0x8da0, 0xa9c0, 0xb5e0};

/*
 * Sets output to x times H using the precomputed tables.
 * x and output are seen as elements of GF(2^128) as in [MGV].
 */
static void gcm_mult(mbedtls_gcm_context* ctx, const unsigned char x[16], unsigned char output[16])
{
    int i = 0;
    unsigned char lo, hi, rem;
    uint64_t zh, zl;

    lo = x[15] & 0xf;

    zh = ctx->HH[lo];
    zl = ctx->HL[lo];

    for (i = 15; i >= 0; i--) {
        lo = x[i] & 0xf;
        hi = x[i] >> 4;

        if (i != 15) {
            rem = (unsigned char)zl & 0xf;
            zl = (zh << 60) | (zl >> 4);
            zh = (zh >> 4);
            zh ^= (uint64_t)last4[rem] << 48;
            zh ^= ctx->HH[lo];
            zl ^= ctx->HL[lo];
        }

        rem = (unsigned char)zl & 0xf;
        zl = (zh << 60) | (zl >> 4);
        zh = (zh >> 4);
        zh ^= (uint64_t)last4[rem] << 48;
        zh ^= ctx->HH[hi];
        zl ^= ctx->HL[hi];
    }

    PUT_UINT32_BE(zh >> 32, output, 0);
    PUT_UINT32_BE(zh, output, 4);
    PUT_UINT32_BE(zl >> 32, output, 8);
    PUT_UINT32_BE(zl, output, 12);
}

int mbedtls_gcm_starts(mbedtls_gcm_context* ctx, int mode, const unsigned char* iv, size_t iv_len, const unsigned char* add, size_t add_len)
{
    int ret;
    unsigned char work_buf[16];
    size_t i;
    const unsigned char* p;
    size_t use_len, olen = 0;

    GCM_VALIDATE_RET(ctx != NULL);
    GCM_VALIDATE_RET(iv != NULL);
    GCM_VALIDATE_RET(add_len == 0 || add != NULL);

    /* IV and AD are limited to 2^64 bits, so 2^61 bytes */
    /* IV is not allowed to be zero length */
    if (iv_len == 0 || ((uint64_t)iv_len) >> 61 != 0 || ((uint64_t)add_len) >> 61 != 0) {
        return (MBEDTLS_ERR_GCM_BAD_INPUT);
    }

    memset(ctx->y, 0x00, sizeof(ctx->y));
    memset(ctx->buf, 0x00, sizeof(ctx->buf));

    ctx->mode = mode;
    ctx->len = 0;
    ctx->add_len = 0;

    if (iv_len == 12) {
        memcpy(ctx->y, iv, iv_len);
        ctx->y[15] = 1;
    } else {
        memset(work_buf, 0x00, 16);
        PUT_UINT32_BE(iv_len * 8, work_buf, 12);

        p = iv;
        while (iv_len > 0) {
            use_len = (iv_len < 16) ? iv_len : 16;

            for (i = 0; i < use_len; i++)
                ctx->y[i] ^= p[i];

            gcm_mult(ctx, ctx->y, ctx->y);

            iv_len -= use_len;
            p += use_len;
        }

        for (i = 0; i < 16; i++)
            ctx->y[i] ^= work_buf[i];

        gcm_mult(ctx, ctx->y, ctx->y);
    }

    if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->base_ectr, &olen)) != 0) {
        return (ret);
    }

    ctx->add_len = add_len;
    p = add;
    while (add_len > 0) {
        use_len = (add_len < 16) ? add_len : 16;

        for (i = 0; i < use_len; i++)
            ctx->buf[i] ^= p[i];

        gcm_mult(ctx, ctx->buf, ctx->buf);

        add_len -= use_len;
        p += use_len;
    }

    return (0);
}

int mbedtls_gcm_update(mbedtls_gcm_context* ctx, size_t length, const unsigned char* input, unsigned char* output)
{
    int ret;
    unsigned char ectr[16];
    size_t i;
    const unsigned char* p;
    unsigned char* out_p = output;
    size_t use_len, olen = 0;

    GCM_VALIDATE_RET(ctx != NULL);
    GCM_VALIDATE_RET(length == 0 || input != NULL);
    GCM_VALIDATE_RET(length == 0 || output != NULL);

    if (output > input && (size_t)(output - input) < length)
        return (MBEDTLS_ERR_GCM_BAD_INPUT);

    /* Total length is restricted to 2^39 - 256 bits, ie 2^36 - 2^5 bytes
     * Also check for possible overflow */
    if (ctx->len + length < ctx->len || (uint64_t)ctx->len + length > 0xFFFFFFFE0ull) {
        return (MBEDTLS_ERR_GCM_BAD_INPUT);
    }

    ctx->len += length;

    p = input;
    while (length > 0) {
        use_len = (length < 16) ? length : 16;

        for (i = 16; i > 12; i--)
            if (++ctx->y[i - 1] != 0)
                break;

        if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ectr, &olen)) != 0) {
            return (ret);
        }

        for (i = 0; i < use_len; i++) {
            if (ctx->mode == MBEDTLS_GCM_DECRYPT)
                ctx->buf[i] ^= p[i];
            out_p[i] = ectr[i] ^ p[i];
            if (ctx->mode == MBEDTLS_GCM_ENCRYPT)
                ctx->buf[i] ^= out_p[i];
        }

        gcm_mult(ctx, ctx->buf, ctx->buf);

        length -= use_len;
        p += use_len;
        out_p += use_len;
    }

    return (0);
}

int mbedtls_gcm_finish(mbedtls_gcm_context* ctx, unsigned char* tag, size_t tag_len)
{
    unsigned char work_buf[16];
    size_t i;
    uint64_t orig_len;
    uint64_t orig_add_len;

    GCM_VALIDATE_RET(ctx != NULL);
    GCM_VALIDATE_RET(tag != NULL);

    orig_len = ctx->len * 8;
    orig_add_len = ctx->add_len * 8;

    if (tag_len > 16 || tag_len < 4)
        return (MBEDTLS_ERR_GCM_BAD_INPUT);

    memcpy(tag, ctx->base_ectr, tag_len);

    if (orig_len || orig_add_len) {
        memset(work_buf, 0x00, 16);

        PUT_UINT32_BE((orig_add_len >> 32), work_buf, 0);
        PUT_UINT32_BE((orig_add_len), work_buf, 4);
        PUT_UINT32_BE((orig_len >> 32), work_buf, 8);
        PUT_UINT32_BE((orig_len), work_buf, 12);

        for (i = 0; i < 16; i++)
            ctx->buf[i] ^= work_buf[i];

        gcm_mult(ctx, ctx->buf, ctx->buf);

        for (i = 0; i < tag_len; i++)
            tag[i] ^= ctx->buf[i];
    }

    return (0);
}

int mbedtls_gcm_crypt_and_tag(
    mbedtls_gcm_context* ctx,
    int mode,
    size_t length,
    const unsigned char* iv,
    size_t iv_len,
    const unsigned char* add,
    size_t add_len,
    const unsigned char* input,
    unsigned char* output,
    size_t tag_len,
    unsigned char* tag)
{
    int ret;

    GCM_VALIDATE_RET(ctx != NULL);
    GCM_VALIDATE_RET(iv != NULL);
    GCM_VALIDATE_RET(add_len == 0 || add != NULL);
    GCM_VALIDATE_RET(length == 0 || input != NULL);
    GCM_VALIDATE_RET(length == 0 || output != NULL);
    GCM_VALIDATE_RET(tag != NULL);

    if ((ret = mbedtls_gcm_starts(ctx, mode, iv, iv_len, add, add_len)) != 0)
        return (ret);

    if ((ret = mbedtls_gcm_update(ctx, length, input, output)) != 0)
        return (ret);

    if ((ret = mbedtls_gcm_finish(ctx, tag, tag_len)) != 0)
        return (ret);

    return (0);
}

int mbedtls_gcm_auth_decrypt(
    mbedtls_gcm_context* ctx,
    size_t length,
    const unsigned char* iv,
    size_t iv_len,
    const unsigned char* add,
    size_t add_len,
    const unsigned char* tag,
    size_t tag_len,
    const unsigned char* input,
    unsigned char* output)
{
    int ret;
    unsigned char check_tag[16];
    size_t i;
    int diff;

    GCM_VALIDATE_RET(ctx != NULL);
    GCM_VALIDATE_RET(iv != NULL);
    GCM_VALIDATE_RET(add_len == 0 || add != NULL);
    GCM_VALIDATE_RET(tag != NULL);
    GCM_VALIDATE_RET(length == 0 || input != NULL);
    GCM_VALIDATE_RET(length == 0 || output != NULL);

    if ((ret = mbedtls_gcm_crypt_and_tag(ctx, MBEDTLS_GCM_DECRYPT, length, iv, iv_len, add, add_len, input, output, tag_len, check_tag)) != 0) {
        return (ret);
    }

    /* Check tag in "constant-time" */
    for (diff = 0, i = 0; i < tag_len; i++)
        diff |= tag[i] ^ check_tag[i];

    if (diff != 0) {
        mbedtls_platform_zeroize(output, length);
        return (MBEDTLS_ERR_GCM_AUTH_FAILED);
    }

    return (0);
}

void mbedtls_gcm_free(mbedtls_gcm_context* ctx)
{
    if (ctx == NULL)
        return;
    mbedtls_cipher_free(&ctx->cipher_ctx);
    mbedtls_platform_zeroize(ctx, sizeof(mbedtls_gcm_context));
}

#endif /* !MBEDTLS_GCM_ALT */

#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
/*
 * AES-GCM test vectors from:
 *
 * http://csrc.nist.gov/groups/STM/cavp/documents/mac/gcmtestvectors.zip
 */
#define MAX_TESTS 6

static const int key_index[MAX_TESTS] = {0, 0, 1, 1, 1, 1};

static const unsigned char key[MAX_TESTS][32] = {
    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
    {0xfe, 0xff, 0xe9, 0x92, 0x86, 0x65, 0x73, 0x1c, 0x6d, 0x6a, 0x8f, 0x94, 0x67, 0x30, 0x83, 0x08,
     0xfe, 0xff, 0xe9, 0x92, 0x86, 0x65, 0x73, 0x1c, 0x6d, 0x6a, 0x8f, 0x94, 0x67, 0x30, 0x83, 0x08},
};

static const size_t iv_len[MAX_TESTS] = {12, 12, 12, 12, 8, 60};

static const int iv_index[MAX_TESTS] = {0, 0, 1, 1, 1, 2};

static const unsigned char iv[MAX_TESTS][64] = {
    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
    {0xca, 0xfe, 0xba, 0xbe, 0xfa, 0xce, 0xdb, 0xad, 0xde, 0xca, 0xf8, 0x88},
    {0x93, 0x13, 0x22, 0x5d, 0xf8, 0x84, 0x06, 0xe5, 0x55, 0x90, 0x9c, 0x5a, 0xff, 0x52, 0x69, 0xaa, 0x6a, 0x7a, 0x95, 0x38,
     0x53, 0x4f, 0x7d, 0xa1, 0xe4, 0xc3, 0x03, 0xd2, 0xa3, 0x18, 0xa7, 0x28, 0xc3, 0xc0, 0xc9, 0x51, 0x56, 0x80, 0x95, 0x39,
     0xfc, 0xf0, 0xe2, 0x42, 0x9a, 0x6b, 0x52, 0x54, 0x16, 0xae, 0xdb, 0xf5, 0xa0, 0xde, 0x6a, 0x57, 0xa6, 0x37, 0xb3, 0x9b},
};

static const size_t add_len[MAX_TESTS] = {0, 0, 0, 20, 20, 20};

static const int add_index[MAX_TESTS] = {0, 0, 0, 1, 1, 1};

static const unsigned char additional[MAX_TESTS][64] = {
    {0x00},
    {0xfe, 0xed, 0xfa, 0xce, 0xde, 0xad, 0xbe, 0xef, 0xfe, 0xed, 0xfa, 0xce, 0xde, 0xad, 0xbe, 0xef, 0xab, 0xad, 0xda, 0xd2},
};

static const size_t pt_len[MAX_TESTS] = {0, 16, 64, 60, 60, 60};

static const int pt_index[MAX_TESTS] = {0, 0, 1, 1, 1, 1};

static const unsigned char pt[MAX_TESTS][64] = {
    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
    {0xd9, 0x31, 0x32, 0x25, 0xf8, 0x84, 0x06, 0xe5, 0xa5, 0x59, 0x09, 0xc5, 0xaf, 0xf5, 0x26, 0x9a, 0x86, 0xa7, 0xa9, 0x53, 0x15, 0x34,
     0xf7, 0xda, 0x2e, 0x4c, 0x30, 0x3d, 0x8a, 0x31, 0x8a, 0x72, 0x1c, 0x3c, 0x0c, 0x95, 0x95, 0x68, 0x09, 0x53, 0x2f, 0xcf, 0x0e, 0x24,
     0x49, 0xa6, 0xb5, 0x25, 0xb1, 0x6a, 0xed, 0xf5, 0xaa, 0x0d, 0xe6, 0x57, 0xba, 0x63, 0x7b, 0x39, 0x1a, 0xaf, 0xd2, 0x55},
};

static const unsigned char ct[MAX_TESTS * 3][64] = {
    {0x00},
    {0x03, 0x88, 0xda, 0xce, 0x60, 0xb6, 0xa3, 0x92, 0xf3, 0x28, 0xc2, 0xb9, 0x71, 0xb2, 0xfe, 0x78},
    {0x42, 0x83, 0x1e, 0xc2, 0x21, 0x77, 0x74, 0x24, 0x4b, 0x72, 0x21, 0xb7, 0x84, 0xd0, 0xd4, 0x9c, 0xe3, 0xaa, 0x21, 0x2f, 0x2c, 0x02,
     0xa4, 0xe0, 0x35, 0xc1, 0x7e, 0x23, 0x29, 0xac, 0xa1, 0x2e, 0x21, 0xd5, 0x14, 0xb2, 0x54, 0x66, 0x93, 0x1c, 0x7d, 0x8f, 0x6a, 0x5a,
     0xac, 0x84, 0xaa, 0x05, 0x1b, 0xa3, 0x0b, 0x39, 0x6a, 0x0a, 0xac, 0x97, 0x3d, 0x58, 0xe0, 0x91, 0x47, 0x3f, 0x59, 0x85},
    {0x42, 0x83, 0x1e, 0xc2, 0x21, 0x77, 0x74, 0x24, 0x4b, 0x72, 0x21, 0xb7, 0x84, 0xd0, 0xd4, 0x9c, 0xe3, 0xaa, 0x21, 0x2f,
     0x2c, 0x02, 0xa4, 0xe0, 0x35, 0xc1, 0x7e, 0x23, 0x29, 0xac, 0xa1, 0x2e, 0x21, 0xd5, 0x14, 0xb2, 0x54, 0x66, 0x93, 0x1c,
     0x7d, 0x8f, 0x6a, 0x5a, 0xac, 0x84, 0xaa, 0x05, 0x1b, 0xa3, 0x0b, 0x39, 0x6a, 0x0a, 0xac, 0x97, 0x3d, 0x58, 0xe0, 0x91},
    {0x61, 0x35, 0x3b, 0x4c, 0x28, 0x06, 0x93, 0x4a, 0x77, 0x7f, 0xf5, 0x1f, 0xa2, 0x2a, 0x47, 0x55, 0x69, 0x9b, 0x2a, 0x71,
     0x4f, 0xcd, 0xc6, 0xf8, 0x37, 0x66, 0xe5, 0xf9, 0x7b, 0x6c, 0x74, 0x23, 0x73, 0x80, 0x69, 0x00, 0xe4, 0x9f, 0x24, 0xb2,
     0x2b, 0x09, 0x75, 0x44, 0xd4, 0x89, 0x6b, 0x42, 0x49, 0x89, 0xb5, 0xe1, 0xeb, 0xac, 0x0f, 0x07, 0xc2, 0x3f, 0x45, 0x98},
    {0x8c, 0xe2, 0x49, 0x98, 0x62, 0x56, 0x15, 0xb6, 0x03, 0xa0, 0x33, 0xac, 0xa1, 0x3f, 0xb8, 0x94, 0xbe, 0x91, 0x12, 0xa5,
     0xc3, 0xa2, 0x11, 0xa8, 0xba, 0x26, 0x2a, 0x3c, 0xca, 0x7e, 0x2c, 0xa7, 0x01, 0xe4, 0xa9, 0xa4, 0xfb, 0xa4, 0x3c, 0x90,
     0xcc, 0xdc, 0xb2, 0x81, 0xd4, 0x8c, 0x7c, 0x6f, 0xd6, 0x28, 0x75, 0xd2, 0xac, 0xa4, 0x17, 0x03, 0x4c, 0x34, 0xae, 0xe5},
    {0x00},
    {0x98, 0xe7, 0x24, 0x7c, 0x07, 0xf0, 0xfe, 0x41, 0x1c, 0x26, 0x7e, 0x43, 0x84, 0xb0, 0xf6, 0x00},
    {0x39, 0x80, 0xca, 0x0b, 0x3c, 0x00, 0xe8, 0x41, 0xeb, 0x06, 0xfa, 0xc4, 0x87, 0x2a, 0x27, 0x57, 0x85, 0x9e, 0x1c, 0xea, 0xa6, 0xef,
     0xd9, 0x84, 0x62, 0x85, 0x93, 0xb4, 0x0c, 0xa1, 0xe1, 0x9c, 0x7d, 0x77, 0x3d, 0x00, 0xc1, 0x44, 0xc5, 0x25, 0xac, 0x61, 0x9d, 0x18,
     0xc8, 0x4a, 0x3f, 0x47, 0x18, 0xe2, 0x44, 0x8b, 0x2f, 0xe3, 0x24, 0xd9, 0xcc, 0xda, 0x27, 0x10, 0xac, 0xad, 0xe2, 0x56},
    {0x39, 0x80, 0xca, 0x0b, 0x3c, 0x00, 0xe8, 0x41, 0xeb, 0x06, 0xfa, 0xc4, 0x87, 0x2a, 0x27, 0x57, 0x85, 0x9e, 0x1c, 0xea,
     0xa6, 0xef, 0xd9, 0x84, 0x62, 0x85, 0x93, 0xb4, 0x0c, 0xa1, 0xe1, 0x9c, 0x7d, 0x77, 0x3d, 0x00, 0xc1, 0x44, 0xc5, 0x25,
     0xac, 0x61, 0x9d, 0x18, 0xc8, 0x4a, 0x3f, 0x47, 0x18, 0xe2, 0x44, 0x8b, 0x2f, 0xe3, 0x24, 0xd9, 0xcc, 0xda, 0x27, 0x10},
    {0x0f, 0x10, 0xf5, 0x99, 0xae, 0x14, 0xa1, 0x54, 0xed, 0x24, 0xb3, 0x6e, 0x25, 0x32, 0x4d, 0xb8, 0xc5, 0x66, 0x63, 0x2e,
     0xf2, 0xbb, 0xb3, 0x4f, 0x83, 0x47, 0x28, 0x0f, 0xc4, 0x50, 0x70, 0x57, 0xfd, 0xdc, 0x29, 0xdf, 0x9a, 0x47, 0x1f, 0x75,
     0xc6, 0x65, 0x41, 0xd4, 0xd4, 0xda, 0xd1, 0xc9, 0xe9, 0x3a, 0x19, 0xa5, 0x8e, 0x8b, 0x47, 0x3f, 0xa0, 0xf0, 0x62, 0xf7},
    {0xd2, 0x7e, 0x88, 0x68, 0x1c, 0xe3, 0x24, 0x3c, 0x48, 0x30, 0x16, 0x5a, 0x8f, 0xdc, 0xf9, 0xff, 0x1d, 0xe9, 0xa1, 0xd8,
     0xe6, 0xb4, 0x47, 0xef, 0x6e, 0xf7, 0xb7, 0x98, 0x28, 0x66, 0x6e, 0x45, 0x81, 0xe7, 0x90, 0x12, 0xaf, 0x34, 0xdd, 0xd9,
     0xe2, 0xf0, 0x37, 0x58, 0x9b, 0x29, 0x2d, 0xb3, 0xe6, 0x7c, 0x03, 0x67, 0x45, 0xfa, 0x22, 0xe7, 0xe9, 0xb7, 0x37, 0x3b},
    {0x00},
    {0xce, 0xa7, 0x40, 0x3d, 0x4d, 0x60, 0x6b, 0x6e, 0x07, 0x4e, 0xc5, 0xd3, 0xba, 0xf3, 0x9d, 0x18},
    {0x52, 0x2d, 0xc1, 0xf0, 0x99, 0x56, 0x7d, 0x07, 0xf4, 0x7f, 0x37, 0xa3, 0x2a, 0x84, 0x42, 0x7d, 0x64, 0x3a, 0x8c, 0xdc, 0xbf, 0xe5,
     0xc0, 0xc9, 0x75, 0x98, 0xa2, 0xbd, 0x25, 0x55, 0xd1, 0xaa, 0x8c, 0xb0, 0x8e, 0x48, 0x59, 0x0d, 0xbb, 0x3d, 0xa7, 0xb0, 0x8b, 0x10,
     0x56, 0x82, 0x88, 0x38, 0xc5, 0xf6, 0x1e, 0x63, 0x93, 0xba, 0x7a, 0x0a, 0xbc, 0xc9, 0xf6, 0x62, 0x89, 0x80, 0x15, 0xad},
    {0x52, 0x2d, 0xc1, 0xf0, 0x99, 0x56, 0x7d, 0x07, 0xf4, 0x7f, 0x37, 0xa3, 0x2a, 0x84, 0x42, 0x7d, 0x64, 0x3a, 0x8c, 0xdc,
     0xbf, 0xe5, 0xc0, 0xc9, 0x75, 0x98, 0xa2, 0xbd, 0x25, 0x55, 0xd1, 0xaa, 0x8c, 0xb0, 0x8e, 0x48, 0x59, 0x0d, 0xbb, 0x3d,
     0xa7, 0xb0, 0x8b, 0x10, 0x56, 0x82, 0x88, 0x38, 0xc5, 0xf6, 0x1e, 0x63, 0x93, 0xba, 0x7a, 0x0a, 0xbc, 0xc9, 0xf6, 0x62},
    {0xc3, 0x76, 0x2d, 0xf1, 0xca, 0x78, 0x7d, 0x32, 0xae, 0x47, 0xc1, 0x3b, 0xf1, 0x98, 0x44, 0xcb, 0xaf, 0x1a, 0xe1, 0x4d,
     0x0b, 0x97, 0x6a, 0xfa, 0xc5, 0x2f, 0xf7, 0xd7, 0x9b, 0xba, 0x9d, 0xe0, 0xfe, 0xb5, 0x82, 0xd3, 0x39, 0x34, 0xa4, 0xf0,
     0x95, 0x4c, 0xc2, 0x36, 0x3b, 0xc7, 0x3f, 0x78, 0x62, 0xac, 0x43, 0x0e, 0x64, 0xab, 0xe4, 0x99, 0xf4, 0x7c, 0x9b, 0x1f},
    {0x5a, 0x8d, 0xef, 0x2f, 0x0c, 0x9e, 0x53, 0xf1, 0xf7, 0x5d, 0x78, 0x53, 0x65, 0x9e, 0x2a, 0x20, 0xee, 0xb2, 0xb2, 0x2a,
     0xaf, 0xde, 0x64, 0x19, 0xa0, 0x58, 0xab, 0x4f, 0x6f, 0x74, 0x6b, 0xf4, 0x0f, 0xc0, 0xc3, 0xb7, 0x80, 0xf2, 0x44, 0x45,
     0x2d, 0xa3, 0xeb, 0xf1, 0xc5, 0xd8, 0x2c, 0xde, 0xa2, 0x41, 0x89, 0x97, 0x20, 0x0e, 0xf8, 0x2e, 0x44, 0xae, 0x7e, 0x3f},
};

static const unsigned char tag[MAX_TESTS * 3][16] = {
    {0x58, 0xe2, 0xfc, 0xce, 0xfa, 0x7e, 0x30, 0x61, 0x36, 0x7f, 0x1d, 0x57, 0xa4, 0xe7, 0x45, 0x5a},
    {0xab, 0x6e, 0x47, 0xd4, 0x2c, 0xec, 0x13, 0xbd, 0xf5, 0x3a, 0x67, 0xb2, 0x12, 0x57, 0xbd, 0xdf},
    {0x4d, 0x5c, 0x2a, 0xf3, 0x27, 0xcd, 0x64, 0xa6, 0x2c, 0xf3, 0x5a, 0xbd, 0x2b, 0xa6, 0xfa, 0xb4},
    {0x5b, 0xc9, 0x4f, 0xbc, 0x32, 0x21, 0xa5, 0xdb, 0x94, 0xfa, 0xe9, 0x5a, 0xe7, 0x12, 0x1a, 0x47},
    {0x36, 0x12, 0xd2, 0xe7, 0x9e, 0x3b, 0x07, 0x85, 0x56, 0x1b, 0xe1, 0x4a, 0xac, 0xa2, 0xfc, 0xcb},
    {0x61, 0x9c, 0xc5, 0xae, 0xff, 0xfe, 0x0b, 0xfa, 0x46, 0x2a, 0xf4, 0x3c, 0x16, 0x99, 0xd0, 0x50},
    {0xcd, 0x33, 0xb2, 0x8a, 0xc7, 0x73, 0xf7, 0x4b, 0xa0, 0x0e, 0xd1, 0xf3, 0x12, 0x57, 0x24, 0x35},
    {0x2f, 0xf5, 0x8d, 0x80, 0x03, 0x39, 0x27, 0xab, 0x8e, 0xf4, 0xd4, 0x58, 0x75, 0x14, 0xf0, 0xfb},
    {0x99, 0x24, 0xa7, 0xc8, 0x58, 0x73, 0x36, 0xbf, 0xb1, 0x18, 0x02, 0x4d, 0xb8, 0x67, 0x4a, 0x14},
    {0x25, 0x19, 0x49, 0x8e, 0x80, 0xf1, 0x47, 0x8f, 0x37, 0xba, 0x55, 0xbd, 0x6d, 0x27, 0x61, 0x8c},
    {0x65, 0xdc, 0xc5, 0x7f, 0xcf, 0x62, 0x3a, 0x24, 0x09, 0x4f, 0xcc, 0xa4, 0x0d, 0x35, 0x33, 0xf8},
    {0xdc, 0xf5, 0x66, 0xff, 0x29, 0x1c, 0x25, 0xbb, 0xb8, 0x56, 0x8f, 0xc3, 0xd3, 0x76, 0xa6, 0xd9},
    {0x53, 0x0f, 0x8a, 0xfb, 0xc7, 0x45, 0x36, 0xb9, 0xa9, 0x63, 0xb4, 0xf1, 0xc4, 0xcb, 0x73, 0x8b},
    {0xd0, 0xd1, 0xc8, 0xa7, 0x99, 0x99, 0x6b, 0xf0, 0x26, 0x5b, 0x98, 0xb5, 0xd4, 0x8a, 0xb9, 0x19},
    {0xb0, 0x94, 0xda, 0xc5, 0xd9, 0x34, 0x71, 0xbd, 0xec, 0x1a, 0x50, 0x22, 0x70, 0xe3, 0xcc, 0x6c},
    {0x76, 0xfc, 0x6e, 0xce, 0x0f, 0x4e, 0x17, 0x68, 0xcd, 0xdf, 0x88, 0x53, 0xbb, 0x2d, 0x55, 0x1b},
    {0x3a, 0x33, 0x7d, 0xbf, 0x46, 0xa7, 0x92, 0xc4, 0x5e, 0x45, 0x49, 0x13, 0xfe, 0x2e, 0xa8, 0xf2},
    {0xa4, 0x4a, 0x82, 0x66, 0xee, 0x1c, 0x8e, 0xb0, 0xc8, 0xb5, 0xd4, 0xcf, 0x5a, 0xe9, 0xf1, 0x9a},
};

int mbedtls_gcm_self_test(int verbose)
{
    mbedtls_gcm_context ctx;
    unsigned char buf[64];
    unsigned char tag_buf[16];
    int i, j, ret;
    mbedtls_cipher_id_t cipher = MBEDTLS_CIPHER_ID_AES;

    for (j = 0; j < 3; j++) {
        int key_len = 128 + 64 * j;

        for (i = 0; i < MAX_TESTS; i++) {
            mbedtls_gcm_init(&ctx);

            if (verbose != 0)
                mbedtls_printf("  AES-GCM-%3d #%d (%s): ", key_len, i, "enc");

            ret = mbedtls_gcm_setkey(&ctx, cipher, key[key_index[i]], key_len);
            /*
             * AES-192 is an optional feature that may be unavailable when
             * there is an alternative underlying implementation i.e. when
             * MBEDTLS_AES_ALT is defined.
             */
            if (ret == MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED && key_len == 192) {
                mbedtls_printf("skipped\n");
                break;
            } else if (ret != 0) {
                goto exit;
            }

            ret = mbedtls_gcm_crypt_and_tag(
                &ctx, MBEDTLS_GCM_ENCRYPT, pt_len[i], iv[iv_index[i]], iv_len[i], additional[add_index[i]], add_len[i], pt[pt_index[i]], buf, 16,
                tag_buf);
            if (ret != 0)
                goto exit;

            if (memcmp(buf, ct[j * 6 + i], pt_len[i]) != 0 || memcmp(tag_buf, tag[j * 6 + i], 16) != 0) {
                ret = 1;
                goto exit;
            }

            mbedtls_gcm_free(&ctx);

            if (verbose != 0)
                mbedtls_printf("passed\n");

            mbedtls_gcm_init(&ctx);

            if (verbose != 0)
                mbedtls_printf("  AES-GCM-%3d #%d (%s): ", key_len, i, "dec");

            ret = mbedtls_gcm_setkey(&ctx, cipher, key[key_index[i]], key_len);
            if (ret != 0)
                goto exit;

            ret = mbedtls_gcm_crypt_and_tag(
                &ctx, MBEDTLS_GCM_DECRYPT, pt_len[i], iv[iv_index[i]], iv_len[i], additional[add_index[i]], add_len[i], ct[j * 6 + i], buf, 16,
                tag_buf);

            if (ret != 0)
                goto exit;

            if (memcmp(buf, pt[pt_index[i]], pt_len[i]) != 0 || memcmp(tag_buf, tag[j * 6 + i], 16) != 0) {
                ret = 1;
                goto exit;
            }

            mbedtls_gcm_free(&ctx);

            if (verbose != 0)
                mbedtls_printf("passed\n");

            mbedtls_gcm_init(&ctx);

            if (verbose != 0)
                mbedtls_printf("  AES-GCM-%3d #%d split (%s): ", key_len, i, "enc");

            ret = mbedtls_gcm_setkey(&ctx, cipher, key[key_index[i]], key_len);
            if (ret != 0)
                goto exit;

            ret = mbedtls_gcm_starts(&ctx, MBEDTLS_GCM_ENCRYPT, iv[iv_index[i]], iv_len[i], additional[add_index[i]], add_len[i]);
            if (ret != 0)
                goto exit;

            if (pt_len[i] > 32) {
                size_t rest_len = pt_len[i] - 32;
                ret = mbedtls_gcm_update(&ctx, 32, pt[pt_index[i]], buf);
                if (ret != 0)
                    goto exit;

                ret = mbedtls_gcm_update(&ctx, rest_len, pt[pt_index[i]] + 32, buf + 32);
                if (ret != 0)
                    goto exit;
            } else {
                ret = mbedtls_gcm_update(&ctx, pt_len[i], pt[pt_index[i]], buf);
                if (ret != 0)
                    goto exit;
            }

            ret = mbedtls_gcm_finish(&ctx, tag_buf, 16);
            if (ret != 0)
                goto exit;

            if (memcmp(buf, ct[j * 6 + i], pt_len[i]) != 0 || memcmp(tag_buf, tag[j * 6 + i], 16) != 0) {
                ret = 1;
                goto exit;
            }

            mbedtls_gcm_free(&ctx);

            if (verbose != 0)
                mbedtls_printf("passed\n");

            mbedtls_gcm_init(&ctx);

            if (verbose != 0)
                mbedtls_printf("  AES-GCM-%3d #%d split (%s): ", key_len, i, "dec");

            ret = mbedtls_gcm_setkey(&ctx, cipher, key[key_index[i]], key_len);
            if (ret != 0)
                goto exit;

            ret = mbedtls_gcm_starts(&ctx, MBEDTLS_GCM_DECRYPT, iv[iv_index[i]], iv_len[i], additional[add_index[i]], add_len[i]);
            if (ret != 0)
                goto exit;

            if (pt_len[i] > 32) {
                size_t rest_len = pt_len[i] - 32;
                ret = mbedtls_gcm_update(&ctx, 32, ct[j * 6 + i], buf);
                if (ret != 0)
                    goto exit;

                ret = mbedtls_gcm_update(&ctx, rest_len, ct[j * 6 + i] + 32, buf + 32);
                if (ret != 0)
                    goto exit;
            } else {
                ret = mbedtls_gcm_update(&ctx, pt_len[i], ct[j * 6 + i], buf);
                if (ret != 0)
                    goto exit;
            }

            ret = mbedtls_gcm_finish(&ctx, tag_buf, 16);
            if (ret != 0)
                goto exit;

            if (memcmp(buf, pt[pt_index[i]], pt_len[i]) != 0 || memcmp(tag_buf, tag[j * 6 + i], 16) != 0) {
                ret = 1;
                goto exit;
            }

            mbedtls_gcm_free(&ctx);

            if (verbose != 0)
                mbedtls_printf("passed\n");
        }
    }

    if (verbose != 0)
        mbedtls_printf("\n");

    ret = 0;

exit:
    if (ret != 0) {
        if (verbose != 0)
            mbedtls_printf("failed\n");
        mbedtls_gcm_free(&ctx);
    }

    return (ret);
}

#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */

#endif /* MBEDTLS_GCM_C */
